As an ignition coil for an internal combustion engine, there are those having a primary coil and a secondary coil magnetically coupled to each other, a high voltage connection terminal connected to the secondary coil, and a conduction terminal. The conduction terminal is in contact with the high voltage connection terminal and transmits a high voltage generated in the secondary coil to a spark plug. The primary coil and the secondary coil together with the high voltage connection terminal are accommodated in a case in a state of being sealed by a filling resin. In such an ignition coil, in order to make electrical conduction from the ignition coil to the spark plug, a reliable contact between the high voltage connection terminal and the conduction terminal is required.
Therefore, when manufacturing the ignition coil, in a state before filling the filling resin in the case, the high voltage connection terminal and the conduction terminal are brought into contact with each other, and are brought in a state where the high voltage connection terminal is urged toward the conduction terminal. Thereafter, the filling resin is filled from an opening of the case, and hardened. Thereby, it is possible to obtain the ignition coil in which the high voltage connection terminal is fixed in a state of being in contact with the conduction terminal.
Then, Patent Document 1 discloses that in order to further secure a contact between a high voltage connection terminal and a conduction terminal, two points of the high voltage connection terminal are contacted with a surface on a proximal end side (a surface on a primary coil and a secondary coil side) of the conduction terminal.